I think, you have to switch tactics with your lines, when cars are becoming more and more.
Away from a few trains with high capacity to many trains with lower capacity.
That way you ensure that your frequency is high enough, so people tend to use your trains instead of your cars and that your trains are filled, so you don’t have one train driving full and 3 others, who leave the station empty.
PS: Maybe it helps to spread anxity about communism, because remember, it’s only a small step from mass transit to communism ;P
